Fans at the Sweetlife Music Festival on Saturday (Josh Sisk/Special to the Sun)

Erik MazaThe Baltimore Sun

A party bus company that promised "luxury charter buses" to the Sweetlife Music Festival Saturday is facing a major backlash and thousands of dollars in refunds after it left hundreds of customers stranded.

Numaan Akram, founder and CEO of Rock & Bus, conceded Monday the company screwed up and was working through "hundreds" of complaints to offer refunds to disgruntled customers.

"Unfortunately, we had a serious problem," he said.

On Saturday, some 1,800 people had booked transportation to the festival through the company, Akram said. But about 400 of them, waiting at stops in Dupont Circle and Georgetown in Washington, D.C., were left stranded or picked up late, Akram said.

"NEVER BOOK THROUGH ROCK AND BUS- They stood us up, making my group miss the majority of the concert. We then had to overpay for another way to get there. Completely ruined everything," wrote Britney Bear, just one of scores of customers to leave angry messages on the company's Facebook page.

Geoff Rowson, who paid $40 to be taken from Dupont Circle to Merriweather, described the scene on Saturday as "complete chaos."

"It was a nightmare, but after reading other guests comments on their Facebook page, I can see that it could have been worse," Rowson said. "Our bus was an hour late. A number of people who didn’t originally ride on our bus jumped on, and at one point, a physical altercation took place between guests arguing over seats."

Akram said Rock & Bus, a two-year-old company, uses several charter bus companies to provide trips to major events, like Sweetlife. But on Saturday, one of the charter companies it uses, American Transportation Solutions, canceled six buses at the last minute, leaving Rock & Bus with only 35 buses to accommodate nearly 2,000 customers. George Hadery, director of operations for American, has not responded to requests for comment.

Rock & Bus responded by securing school buses to take people to Sweetlife - "We did everything we could," Akram said - but by the time it had come up with a solution, it was too late for many customers. Akram said only about half of the customers at the two Washington stops got to the festival using the company's substitute school buses.

For Merriweather shows, it charges between $40 and $50 for "luxury transportation" on buses "equipped with TVs, DVD, speaker system, and a restroom" to take people from several locations in Washington, D.C., Virginia and Maryland to the Columbia venue.

Akram expects to refund "many thousands of dollars" to customers, though he declined to estimate how much. He said the company's contract with American was explicit and they're hoping they'll recoup the loss without taking legal action against the charter.